Just to clarify something in case it wasn’t clear before: when you’re learning a language, every word matters. The fact that a word isn’t listed in any JLPT level doesn’t mean it isn’t important. In reality, there are plenty of words and expressions that native speakers use in everyday life that don’t appear in the JLPT at all.
Some people might take this the wrong way and think I’m bragging, but I’ll just say this for context: I passed N1 five years ago, and honestly, you could probably create another level beyond it based on the amount of vocabulary I’ve continued to learn since then.
It’s also worth pointing out that N1 roughly corresponds to C1. Normally there would be another level after that (C2) but the JLPT doesn’t cover that. So the idea that “if it’s not in the JLPT, then it’s not important” doesn’t really make sense.
A good example is the word 奔走 (ほんそう). Even though it’s considered N1 vocabulary, there are plenty of Japanese people who can’t even read it. On the other hand, a word like てんやわんや might sound unusual to some people. I personally didn’t know it until yesterday, but the Japanese person who used it in front of me said it’s a word that supposedly every Japanese person knows. So it doesn’t really make sense to claim that if something isn’t part of a JLPT level, then it isn’t important. Especially if your goal is to eventually reach something close to a native speaker’s level of knowledge.
I’d even go so far as to say that many words native Japanese speakers use in their daily lives that aren’t included in any JLPT level are actually more important than a lot of the vocabulary classified as N1.
by WorkingAlive3258